The present invention relates to a gas burner. It is known that gas burners are devices in which a flow of combustible gas is introduced into a mixing chamber, where it is mixed with a flow of comburent (usually air) supplied in a suitable proportion to the combustible gas. After mixing, the mixture of combustible gas and comburent exits the mixing chamber through a sidewall of said chamber with holes in and is burnt.
The gas is burnt a short distance from the sidewall, which is intensely heated. This heating is localized and its intensity is reduced as the distance between the points of the sidewall and the flame increases.
As a result, the material of which the burner is made is subject to extensive, variable thermal expansion.
When this expansion is prevented, the material of which the burner parts are made is subject to dangerous increases in stress and deformation which, in the most serious cases, may cause parts to give or break. Operating conditions with less intense stress are no less dangerous, since any expansion prevented modifies the geometry of the gas mixture outlet holes, creating the risk of the flame flashing back into the burner.
The present invention relates to a burner of the type comprising: an elongated tubular body with a sidewall between whose outer end edges there are apertures passing right through the sidewall; a flange with central through-hole; a base cap opposite the flange, a truncated cone shaped sector inside the sidewall, open at the end with the smaller diameter, fixed to the sidewall at a point on the end with the larger diameter, and free of other constraints. The sidewall, flange, base cap and truncated cone sector are attached to one another in such a way that together they form a chamber in which a flow of air and gas mixture, received through the hole in the flange, gradually exits the tubular body through the apertures in the sidewall, where the taper of the truncated cone sector reduces the internal passage section gradually as the volume of the internal gaseous mass is reduced because part of said mass exits through the apertures in the sidewall.